Electric mining-machine



(No Model.)

E. A. SPIZRRY.l BLEGTRIG MINING MACHINE.

Patented May 23, 1893.

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UNITED STATES PATENT OEEICE.

ELMER A. SPERRY, OF CI-IICAGO, ILLINOIS, ASSIGNOR, BY MESNE ASSIGNMENTS,TO THE THOMSON-HOUSTON ELECTRIC COMPANY, OF CONNECTICUT.

ELECTRIC MINING-MACHINE.

SPECIFICATION forming part of Letters Patent No. 497,832, dated May 23,1893.

Application led October 8, 1888. Serial No. 2871481. (No model.)

To all whom t may concern.'

Be it known that I, ELMEE A. SPERRY, a citizen of the United States,residing at Chicago, in the county of Cook and State of Illinois, haveinvented a new and useful Electric Mining-Machine, of which thefollowing is a speciiication.

My invention relates to mining machines and has for its object toprovide a cheap and simple automatic mining machine or pick.

My invention is illustrated in the accompanying drawings, wherein-Figure l is a plan view of my machine with parts in section, and Fig. 2is a detail view of the crank automatic releasing mechanism and lostmotion device.

Like parts areindicated by the same letter in both the figures.

A is the frame; B B the trucks and C C the handles.

D is an electric motor mounted on the frame and supplied by means of theconductors D D2 and controlled by the switch D3. This motor operates thepinion E which meshes with the gear E mounted on the shaft E2. Thisshaft carries the pinion E3 which meshes with the gear wheel E4 on theshaft All shafts are mounted on the frame, and, on the same axial linewith the shaft E5, is journaled the gudgeon E6. On the shaft E5 is keyedthe compound camF which with its eccentric curves G and rollers .Iconstitutes a clutch whereby the shaft E5 is at certain times locked tothe crank K. Back of these rollers may he placed springs as K. Cn thegudgeon isa crank K2 and continuous with the cranks K and K2 is thecrank pin K3. A pitman K4 with an elongated slot K5 which receives thecrank pin K3 is at its other end secured to the cross head L, Whichslides in the guide M on the frame and carries at its other end aplunger N' adapted to reciprocate within the dash pot O. The dash pot issecured by the screws O O tothe frame and both are shaped so as to formthe stuffing box P. Projecting from the frame is the guide cylinder R inwhich reciprocates the drill shaft S which is secured to the cross headat its upper end and carries the drill point T at its other end.

U is a sleeve which reciprocates within the substance to be cut.

cylinder R and together with the portion V of the frame forms guides forthe drill and bearings for the spring Wwhich encircles it.

The use and operation of my invention are as follows: When the machineconstructed substantially as shown in the drawings is connected with thepower supplying dynamo it is moved on the trucks and guided by theoperator by means of the handles against the The operation of cutting isperformed by rapid and continuous striking of the drill against thesubstance. The operation of the motor by means of the several gears,pinions and shafts rotates the double crank in the direction indicatedby the arrows in Figs. 1 and 2. This operation of the crank retracts thedrill and compresses the spring thus storing up energy until it reachesthe point z. The crank up to this point in the operation has been lockedto the shaft with which it is concentric by means of the rollers whichpass between the eccentric curves on the compound cam and the concentriccurves on the bore of the crank toward the point where said curvesapproach each other and away from their points of greatest separation.All this is indicated by Fig. 2 and the retracting action of the crankupon the drill is accomplished by the crank pinbearin g against theouter end of the slot in the pitman. Vhen the crank pin has reached thepoint I@the energyT stored in the compressed spring imparts to the drilla velocity greater than that of the moving crank and thereby the crankmoves about its shaft in the direction of the arrow more rapidly thanthe shaft itself moves. Instantly the rollers move toward the point ofgreatest separation of the curves between which they lie and thus thecrank is freed from its shaft and the drill is forced with greatvelocity against the substance to be cut by the direct action of thespring which is first compressed and then instantly released as abovedescribed The dash pot O and plunger N co-operate to form an air cushionto relieve the parts from the concussion which might occur in case thedrill meets with little or no resistance. When the crank and pitman arethus released the stroke of the drill `if it meets with no resistancewould terminate at the point but when the drill meets with ordinaryresistance the effective stroke or blow terminates when the crank pinhas reached the point o or some other point between x and e'. If now theconnection between the pitman and crank pin were positive and unyieldingthe remainder of the stroke would be completed by the action of theshaft upon the crank. For the drill having once been retarded orarrested the crank would in like manner be retarded or arrested so thatits velocity would no longer be greater but less than that of the shaftand instantly the clutch would lock the crank and shaft together. If thedrill were thus retarded or arrested at c the stroke would continueuntil the crank thus aided had passed over the arc from o to x duringwhich portion of the stroke the energy of the machine is exhausted inpushing itself back and away from the work. This tends to interfere withthe effective control and operation of the machine. lf now theconnection between the cross head and the crank be made bya yielding,loose or lost motion connection as foi-instance that shown in Fig. 2 theoperation will be as follows:-- As soon as the crank pin has reached saythe point u at which the drill is for example retarded or arrested theyielding loose or lost motion device will permit the crank pin to passthrough an arc equal to twice the arc v @c without imparting any furthermotion to the drill and this action is instantaneous, whereupon theaction of the clutch instantly locks the crank and shaft together andthe operation of recompressing the spring proceeds before a sufficientperiod of time has elapsed to permit the inertia of the machine to beovercome and thus forced backward. The velocity of the crank and drillafter the pin leaves the point e' is so great that the crank movesthrough the arc double the length ,z .r by the momentum required andthus the drill is given time While unretarded to do its full and mosteffective work while the momentum of the crank itself, in being arrestedat the end of the double arc, gives up its energy in recompressing thespring itself for the next stroke. The process of storing energy, asabove referred to, is important also for it permits the use of anenergizing motor which would not be practicable for direct applicationto the work of drilling. Thus for example a rapidly rotating electricmotor may be made to store up the energy of many revo lutions in adevice which delivers such stored energy in a single blow.

It will be seen from the foregoing that with a constant speed ofrevolution of Vthe energizing or electric mot-or the number ofrevolutions of the crank, and therefore the number of compressions ofthe spring or driving motor may be different. For instance with onehundred and fifty-six revolutions per minute of the wheel E4 and itsshaft the crank will in practice make two hundred and five revolutionsper minute. When the stroke is of full length and the drill is arrestedonly by vits cushion in the front end of the frame;

but irregular with respect to the number of revolutions of theenergizing motor. Y This regularity of number between the revolutions ofthe energizing motor and the strokes of the driving motor is broughtabout by the mechanism by which theyare intermittently locked andreleased from each other. This mechanism l term my irregularly actingcatch, no such irregularly acting catch having heretofore been used inconnection to this art.

It is obvious that the main features of my invention are equallyapplicable to the drilling of rock, coal or other similar substances.

One of the objects of placing the shaft of the motor parallel'with theaxle of the truck is to keep the two in proper relation to each other sothat, no matter what the position of the machine at work may be, theshaft of the motor will have play parallel to the axis of the machine.This greatly facilitates the operation and extends the life of thecommutators and brushes.

The class of mining apparatus to which my IOO invention particularlyextends is that in Y which the machine is constantly moving, beingmanually directible as a part of its operation. It is therefore more inline of an excavator or digger than a drill, the distinction being thatin the latter case while the parts may be heavy and never require thedirectionof its operation to be manually controlled while in action, butonly after its work has been performed, in contra-distinction to this inthe present case the machine should be as light as possible, for if itis not light the operator cannot easily control its operation. Myinvention therefore extends to the use of a moving machine which hasupon it or within it a comparatively small motor, and a device wherebythe power continuously exerted by such motor over a space-of time iscollected or stored and suddenly imparted to the tool, whereby a seriesof powerful actions of the tool or cutter are obtained. This combinationis new and novel, and is enabled to perform a new and useful result fromthe fact that the machine, by being made in this manner, may beconstructed sufciently light in weight that asingle operator can use itfor the purpose of digging or excavating as with a hand pick, and withresults which are al# most in direct proportion to the enormousdifference in the strength ofl the blows attending their userespectively. If the motor were required to operate the cutter by directrtgV connection thereto with equal force, and without the interventionof power storage, the machine would require a motor of great size, soheavy in fact as to render it impossible of control by a singleoperator. A machine of this character, to be of practical utility, mustbe sufficiently light that a single operator may continuously andwithout over-exertion direct all of the operations of the cutter both upand down laterallyin each direction, and also follow in as the cutterpenetrates the material upon which the work is performed. Such movingmachine is supplied with a ilexible connection to the source of powersupply, which in this case may be a llexible electrical conductor orwire.

The clause continuously acting motor used in the following claims ishereby deined as follows: The motor, which may be comparatively small,acting through or by means of the speed reducing gearing E, E', E3, andE4 or the substantial equivalents thereof, together with otherco-operating devices upon the machine, is enabled to gather, accumulateor store the energy or power derived from more than a single, or severalrevolutions or unit impulses into one greatimpulse or work-k doingstroke of the drill bar.

Having thus described my invention, what I claim, and desire to secureby Letters Patent, is as follows:

l. In an excavating machine, the combination of a movable manuallydirectible truck and a supporting frame, a continuously acting motormounted thereon, flexible conductors for conveying energy to the motorfrom a separate source, a cutter-holder or bar reciprocatinglongitudinally in a line passing practically through the center ofinertia of the machine, and a power storing device, as a springreceiving and accumulating tension from the continuously acting motorand discharging the saine at regular intervals through the reciprocatingcutter bar, whereby relatively powerful intermittent blows are deliveredupon the material operated upon, substantially as shown and described.

2. In an excavating machine, the combination of a movable supportingframe, with a continuously acting motor mounted thereon, flexibleconductors for conveying energy to the motor, a cutter holder or barreciprocating longitudinally in a line passing practically through thecenter of inertia of the machine; a power storing device receiving andaccumulating tension from the continuously acting motor and dischargingthe same at regular intervals through the reciprocating cutter bar,whereby relatively powerful intermittent" blows are delivered upon thematerial operated upon, and an intermittent connection and releasebetween the motor shaft and the power storing device whereby the poweris alternately accumulated and automatically released, substantially asshown and described.

3. In an excavating machine, the combination of a movable supportingframe, with a continuously acting motor mounted thereon, flexibleconductors for conveying energy to the' motor a cutter-holder or barreciprocating longitudinally in a line passing practically through thecenter of inertia of the machine, a power storing device receiving andaccumulating tension from the continuously acting motor through a speedreducing gear or gears, and discharging the same at regular intervalsthrough the reciprocating cutterbar, whereby relatively powerfulintermittent blows are delivered upon the material operated upon, and anintermittent connection and release between the motor shaft and thepower storing device, whereby the power is alternately accumulated andautomatically released, substantially as shown and described.

t. In an excavating machine the combination of a movable supportingframe, with a continuously acting electric motor mounted thereon, acutter-holder or bar reciprocating longitudinally in a line passingpractically through the center of inertia of the machine, a powerstoring spring receiving and accumulating tension from the continuouslyacting motor through a speed-reducing gear or gears and discharging thesame at regular intervals through the reciprocating cutter-bar, and acatch to intermittently connect and release the motor and the spring,substantially as and for the purpose shown and described.

5. In an excavating machine, the combination of a movable supportingframe, with a continuously acting electric motor mounted thereon, acutter-holder or bar reciprocating longitudinally in a line passingpractically through the center of inertia of the machine, a powerstoring and delivering spring, operating the cutte1bar,a speed-reducinggear or gears between the motor and the spring, a catch tointermittently connect and release the motor and the spring and acushion device as N O to relieve the machine from the shock of the drillbar when the same is not encountering resistance, substantially as andfor the purpose shown and described.

6. A moving manually directible bi-Wheeled excavating machine,consisting in part of a power motor having the axis of the shaft of themotor parallel with the axis of its supporting wheels, combined with aflexible connection to the source of power supply.

ELMER A. SPERRY.

Witnesses:

FRANCIS W. PARKER, FRANCIS M. IRELAND.

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